Obesity arguably is one of the most serious health problems in the United States as well as the world, affecting millions of people of all ages. Apart from the physical and psychological effects, especially on the younger population, obesity predisposes individuals to serious diseases, such as coronary artery disease, hyperlipidemia, hypertension and diabetes mellitus. The costs to the health system in the United States alone are estimated to be over thirty-nine billion dollars per year.
Weight reduction can be achieved either by increasing caloric expenditures through exercise and/or by reducing caloric intake. Reducing caloric intake can be achieved in a number of ways, such as surgical procedures to reduce the stomach capacity or to reduce the food transit time in the gastrointestinal tract, by using appetite suppressants like amphetamines or noradrenergic compounds, or via other methods, such as introducing balloons into the stomach. The appetite suppressants act on the central nervous system and are associated with considerable morbidity and side effects. Balloon inserts have several disadvantages, which include failure due to bursting or dislodging, intestinal obstruction (blockage of the intestinal lumen), and a requirement of use of complicated devices and/or procedures to secure the balloon within the stomach.
Historically, numerous patents have been issued for devices and methods for treating obesity and other such gastric related ailments. For example, U.S. Pat. No. 4,899,747, issued Feb. 13, 1990, to Garren et al., discloses a method and apparatus for treating obesity. In particular, the apparatus is a flexible, free floating and unattached inflatable balloon that is inserted into the stomach. Upon insertion into the stomach, the balloon is then inflated to reduce the stomach volume of the patient. U.S. Pat. No. 4,694,827, issued Sep. 22, 1987 to Weiner et al., discloses another balloon based approach for treating obesity. In particular, the balloon, when inflated, has a plurality of smooth surfaced convex protrusions disposed in locations that permit the balloon to engage the stomach wall at specific locations.
U.S. Pat. No. 5,686,141, issued Feb. 9, 1999 to Y. A. Ellias, discloses an endoscopic stomach insert having a plurality of flexible blades coupled at one end thereof to a base portion and circumferentially arranged around the central axis of the base. A retainer is provided to releasably couple the distal portions of the blades within close proximity of each other.
U.S. Pat. No. 5,423,872, issued Jun. 13, 1995 to V. Cigaina, discloses a process for treating obesity involving the sequential application of electrical pulses to the stomach for preset periods of time. Another patent to V. Cigaina, i.e., U.S. Pat. No. 6,615,084 issued Sep. 2, 2003, discloses another technique for electro-stimulation of the lesser curvature of the stomach, most preferably on the lower or distal end of the lesser curvature, wherein the lesser curvature is stimulated at a rate of 2-14 pulses per minute.
U.S. Pat. No. 6,540,789, issued Apr. 9, 2003, to Silverman et al., discloses a method for treating morbid obesity involving at least one implant positioned in the wall near the pyloric sphincter to inhibit emptying of the stomach. In yet another example of an implantable device, U.S. Pat. No. 6,611,715, issued Aug. 26, 2003, to B. R. Boveja, discloses an apparatus and method for neuromodulation to treat obesity and compulsive eating disorders using an implantable lead-receiver and an external stimulator. The external stimulator emits electrical pulses that stimulate the vagus nerve. The external stimulator contains a power source, control circuitry, a primary coil, and predetermined programs to control the different levels of therapy.
U.S. Pat. No. 6,627,206, issued Sep. 30, 2003, to G. A. Lloyd, discloses a technique for treating obesity using a mechanism for the time release of medications. In particular, a plurality of space-filling portions are sized to be received within the patient's body, wherein the portions come together in the patient's body to form a structure that provides therapeutic benefits to the patient.
U.S. Pat. No. 6,535,764, issued Mar. 18, 2003 to Imran et al., discloses a device and method for diagnosing and treating gastric disorders. The device is positioned within the stomach of the patient and secured thereto by an attachment mechanism. The device can either be a sensor for sensing various parameters of the stomach or stomach environment or a therapeutic delivery device. In one embodiment, the device provides gastric electrical stimulation, wherein stimulating electrodes are secured to the stomach wall by the attachment mechanism. An electronics unit contains the electronic circuitry of the device, and the device is programmable to respond to the sensed information or signals. An endoscopic delivery system delivers the device through the esophagus into the stomach, wherein the device is attached to the stomach wall. Endoscopic instruments are then attached to the device and attachment mechanism and are used to assist in determining the optimal attachment location on the stomach wall.
U.S. Pat. No. 6,755,869, issued Jun. 29, 2004, to Geitz, discloses a prosthesis formed from a porous weave of bio-absorbable filaments having an open mesh configuration that is formed into an oblate shape having dimensions that are greater than the esophageal opening and gastric outlet of the stomach. The prosthesis is deployed in the stomach to limit the amount of food that may be held within the stomach as well as to apply pressure on the fundus, so as to create a sensation of being full.
Another example of a device for treating obesity and other such gastric ailments includes an elastic band installed around the external wall of the patient's stomach to reduce the internal volume thereof. As a result, the patient requires less food to achieve a sensation of being full and typically loses substantial amounts of weight in a relatively short period of time.
Yet another example of a device that is used to treat obesity and other such gastric ailments is the use of an endoscopic apposition device to sew or suture portions of a patient's stomach tissue together. U.S. Pat. No. 5,080,663, issued Jan. 14, 1992, to Mills et al., U.S. Pat. No. 5,792,153, issued Aug. 11, 1998, to Swain et al., as well as U.S. Patent Application Publication No. 2003/0208209, published Nov. 6, 2003, to Gamble et al., and WO Patent Application Publication No. 2004/103189, published Dec. 2, 2004, to Gamble et al., each disclose various types of endoscopic apposition devices.
Endoscopic apposition devices are used without having to make an external incision in the patient, and are controlled externally of the patient by endoscopic means. Apposition devices typically include a sewing or stapling device for use with a flexible endoscope, although endoscopic apposition devices can also be used with a rigid endoscope.
For example, to stitch or sew together certain portions of stomach tissue, the apposition device, such as a sewing capsule, is attached to the end of a viewing endoscope and inserted through the esophagus of a patient to form a plurality of stitches in stomach tissue slightly below the lower end of the esophagus. A first stitch is made through stomach tissue to one side of the esophagus, and a second stitch is made, with the same suture thread, in stomach tissue adjacent to the first stitch. The two stitches are then drawn together to pull together the diametrically opposed, stitched stomach portions.
After the sutures are applied, the endoscope is removed from the patient and a knot is tied with the free ends of the suture thread that extend outside of the patient. The knot is pushed down to the site of the sutures by a thread guide device that has been positioned at the distal end of the endoscope. The suturing and knotting procedure is repeated several times. After a sufficient number of knots and sutures have been placed, a thread cutter, also operable through the endoscope, is used to cut the suture thread at points that are close to the tissue.
In general, the '663 patent to Mills et al. and the '153 patent to Swain et al. disclose a sewing device positioned on the distal end of an endoscope and used to pass a thread through a portion of stomach tissue. The sewing device includes a hollow needle movable between a first position in which the needle is out of the stomach tissue and a second position in which the needle passes through the portion of stomach tissue, and a thread carrier that is attached to the thread and is received within the needle. The sewing device also includes a body, which defines a cavity within which the portion of stomach tissue is held by a suction force, and within which the needle is mounted for movement between first and second positions.
A more particular or specific description of how the conventional endoscopic appositions devices operate will now be provided using the device disclosed by the '153 patent to Swain et al. as an example. The description of how the device disclosed by the '153 patent to Swain et al. operates will also be instrumental in understanding the differences with the operation and the present invention, which will be described in detail below.
FIGS. 1-3 illustrate the conventional endoscopic apposition device disclosed in the '153 patent to Swain et al.
FIG. 1 shows the distal end of a flexible endoscope 1, on which a sewing device 2 is attached. The endoscope 1 is provided with a viewing channel (not shown), which terminates at a lens on the distal face of the endoscope 1. The endoscope 1 is further provided with a working channel 3 and a suction channel 4, the proximal end of the suction channel 4 being connected to a source of vacuum (not shown).
The sewing device 2 includes a tube 5, which communicates with the suction channel 4, and has a plurality of perforations 6 therein. The perforations 6 communicate with an upwardly open vacuum chamber 7 formed in the sewing device 2.
A hollow needle 8 is mounted in the working channel 3 and has a beveled tip extending into the sewing device 2. The needle 8 has a channel 9 extending therethrough, with a flexible, wire-wound cable 10 attached to the rear of the needle 8. A center wire 11 extends within the cable 10, along the entire length thereof, and is longitudinally movable with respect thereto. The wire 11 is configured to be longitudinally movable within the channel 9 and, in the position shown in FIG. 1, the forward end portion of the wire 11 extends into the rear end portion of the channel 9.
A thread carrier or tag 12 (FIG. 1A) is slidably and releasably mounted in the channel 9. The tag 12 is hollow and has an aperture 13 extending through the sidewall thereof. One end of a thread 14 is secured to the tag 12 after passing through the aperture 13 and being tied in a knot 15 of sufficient size to prevent the thread 14 from slipping out of the tag 14.
A hollow head portion 16, defining a chamber 20 therein, is provided at the distal end of the sewing device 2. A wall 17 is provided between the chamber 20 and the cavity 7, wherein an aperture 18 is formed in the wall 17. The aperture 18 has a diameter that is greater than an external diameter of the needle 8, and is aligned therewith. The clearance between the needle 8 and the aperture 18 must be sufficiently small to prevent stomach tissue from being forced through the aperture 18 and causing the needle 8 to jam. Also, FIG. 1 illustrates a portion of the patient's tissue 19, in which a stitch is to be formed.
In operation, suction is applied to the suction channel 4 and then to the vacuum chamber 7 through the perforations 6 in the tube 5. As shown in FIG. 2, a U-shaped portion 19a of stomach tissue 19 is sucked into the vacuum chamber 7. The needle 8 is then pushed through the U-shaped tissue portion 19a by distally extending the cable 10 and needle 8. After the needle 8 has been fully advanced through both folds of the U-shaped tissue portion 19a, the beveled tip of the needle 8 extends distally beyond the wall 17 and within the chamber 20 in the hollow head portion 16. Distal movement of the wire 11, which is slidably received within the cable 10, pushes the tag 12 out of the channel 9 and into the chamber 20, where the tag 12 rotates out of alignment with the aperture 18 and is captured in the chamber 20.
The wire 11 is then proximally withdrawn, followed by the proximal withdrawal of the cable 10, to withdraw the needle 8 from the U-shaped tissue portion 19a. The suction is then discontinued, allowing the U-shaped tissue portion 19a to be released from the vacuum cavity 7.
As shown in FIG. 3, the released tissue is left with a suture thread 14 passing through the two layers of tissue that form the U-shaped fold 19a. One end of the suture thread 14 is joined to the tag 12 that remains captured in the chamber 20 and the other end of the suture thread 14 extends through the patient's esophagus and out of the mouth. Finally, the endoscope 1 and sewing device 2 are withdrawn from the patient. In so doing, the thread 14 is pulled partially through the tissue portion 19a, as the captured tag 12 is withdrawn proximally and brought outside the patient. With both ends of the thread 14 outside of the patient, the thread 14 is knotted and the knot endoscopically pushed down to the suture site and severed by an endoscopic knot pusher.
The '663 patent to Mills et al, as well as the '209 and '189 published patent applications of Gambale et al., like the device disclosed by the '153 patent to Swain et al., each disclose endoscopic apposition devices wherein the suture thread is retained proximal of the vacuum chamber prior to being threaded through the fold of stomach tissue. Each of these approaches presents certain problems. For example, with each, once the suture thread is passed through the fold of stomach tissue, the suture thread is not retained in a taut manner and may interfere with subsequent sewing or suturing procedures. Additionally, the vacuum channels for each of the conventional apposition devices are provided in the bottom or floor of their respective vacuum chambers. As such, the stomach tissue sucked into vacuum chamber can have a dimpled form. Therefore, the stomach tissue may not be securely retained in the vacuum chamber.
Furthermore, a problem exists in that several conventional devices require the device to be withdrawn from the patient after each stitch or suture made with a single-stitch device. The use of such devices is time consuming, cumbersome, and of some risk to the patient, due, for example, to the multiple intubations and danger of perforations to the esophagus. Also, the patient is required to be kept under sedation for a relatively long period of time.